The foldable table in prior art generally comprises a table top, a leg portion and a supporting portion, the upper end of the leg portion formed rotatable connection with the table top, and the supporting portion comprises a first pivotal-connection portion for pivotally connecting with the leg portion, a second pivotal-connection portion for pivotally connecting with the table top and a ring, the first pivotal-connection portion pivotally connected with the second pivotal-connection portion, the table top, the leg portion, the first pivotal-connection portion and the second pivotal-connection portion formed a four-rod folding mechanism, after being unfolded, the folding mechanism is fixed in an unfolded position by the ring which limit the rotation between the first pivotal-connection portion and the second pivotal-connection portion. After being unfolded, the ring shelved on the connecting portion between the first pivotal-connection portion and the second pivotal-connection portion to prevent they rotating relative to each other, but this locking by the ring is unstable, accordingly, the table is unstable.